Ferf-Butoxide

The submitters employed alcohol-free potassium ferf-butoxide, purchased from K K Laboratories, without further purification the checkers employed comparable material taken from a freshly opened bottle purchased from MSA Research Corporation. The submitters report that among approximately ten different bottles of commercial potassium terf-butoxide used, only material from one bottle failed to form the tricarbonate in this procedure. The defective material in this one bottle was an extremely fine powder that failed to dissolve when... 

Similarly, sodium methoxide (NaOCHj) is a suitable base and is used in methyl alcohol. Potassium hydroxide in ethyl alcohol is another base-solvent combination often employed in the dehydrohalogenation of alkyl halides. Potassium ferf-butoxide [K0C(CH3)3] is the prefened base when the alkyl halide is primary it is used in either terf-butyl alcohol or dimethyl sulfoxide as solvent. 

Some thermal rearrangement reactions of 1-benzoxepins show the participation of the solvent in the formation of stable products, e.g. 6172,247 and 7.177 The synthesis of methoxy-substituted 1-benzoxepins by O-methylation of the anions generated by the deprotonation of the respective oxo derivative with ferf-butoxide is often limited by the rapid aromatization to methoxy-substituted naphthalenes, e.g. 816 and 9,173 under the reaction conditions.16,173... 

Nucleophilic displacement of bromide from 5-acetyl-10-bromo-5//-dibenz[7>,/]azepine (41) by alkoxide,132 and by cyanide ion in dimethylformamide,212 has been noted. However, replacement of bromide by cycloalkylamines (e.g., piperidine) to give the 10-cycloalkylamino derivatives. e.g. 44, is best accomplished in the presence of potassium ferf-butoxide, a result which suggests that the aminodebromination proceeds via an elimination-addition (EA) pathway involving an azepyne intermediate 43 (see Section 3.2.1.5.7.) rather than by the more usual addition-elimination (AF.) mechanism.118... 

Potassium ferf-butoxide was purchased from Columbia Organic Chemicals Company, Columbia, South Carolina. The molar ratio of potassium ferf-butoxide to water is critical, and the amounts specified represent optimum quantities for cleavage of 0.10 mole of ketone.2,3... 

The present synthesis10 consists of two simple steps, uses readily available and inexpensive starting materials, and produces pure material in high overall yield. It is based on two observations that nonenolizable ketones may be cleaved to carboxylic acids by potassium ferf-butoxide-water,2 and that aryl 2 chlorophenyl ketones may be cleaved with loss of the 2-chlorophenyl group to give only one of the two possible acids.11 Other compounds prepared by this route include carboxycyclopentadienyltriearbonylmanganese [Manganese, tricar-bonyl[(l, 2,3,4,5- )-l-carboxy-2,4-cyclopentadien-l-yl]-] (79%)10 and... 

Potassium ferf-butoxide was supplied by Mine Safety Appliances (MSA) Research Corporation. 

B. Benzocyclopropene. A dry, three-necked, round-bottomed flask fitted with a sealed mechanical stirrer, a reflux condenser, and a pressure-equalizing dropping funnel is flushed with nitrogen. To the flask is added 35.0 g (0.312 mole) of potassium ferf-butoxide (Note 1), followed by 200 ml. of dimethyl sulfoxide (Note 5). The stirred mixture is cooled to 15-20° (Note 6) with an ice bath and 24.5 g. 

A pentane solution of terf-butyllithium (purchased from either Alfa Inorganics, Inc. or Lithium Corporation of America, Inc.) was standardized by one of the previously described titration procedures (Note 1). If possible, it is desirable to use a freshly opened bottle of lert-butyllithium since previously used bottles of this reagent often contain lithium ferf-butoxide which will lead to formation of a contaminant in the final product (Note 10). 

Potassium /ert-butoxide See Potassium ferf-butoxide Acids, etc. 

Addition of potassium ferf-butoxide or of sodium isopropoxide to the solvent led to ignition of the latter. This was attributed to presence of free metal in the alkoxides, but a more likely explanation seems to be that of direct interaction between the powerful bases and the sulfoxide. 

A previous method [1] of preparing 3,3-dimethylbutyne by dehydrochlorination of the title compound in a sodium hydroxide melt is difficult to control and hazardous on the large scale. Use of potassium ferf-butoxide as base in DMSO is a high-yielding, safe and convenient alternative method of preparation of the alkyne [2], See Dimethyl sulfoxide Metal alkoxides See other HALOALKANES... 

Potassimn fert-butoxide See Potassimn ferf-butoxide Acids... 

Mesityl oxide Methanol Methylamine N- M et hy lformam i de Methyl isobutyl ketone 2-Aminoethanol, chlorosulfonic acid, nitric acid, ethylenediamine, sulfuric acid Beryllium dihydride, chloroform, oxidants, potassium fcrf-butoxidc Nitromethane Benzenesulfonyl chloride Potassium ferf-butoxide... 

Di-0-isopropylidene-a-D-rtbo-hexofuranos-3-ulose (100) was treated with (chlorofluoromethylene)triphenylphosphorane (prepared by reaction of triphenylphosphine on difluorocarbene generated in situ by reaction of potassium ferf-butoxide with dichloro-fluoromethane), to give cis- and rans-3-C-(chlorofluoromethylene)-3-deoxy-l,2 5,6-di-0-isopropylidene-a-D-ribo- (101 and 103) and -xyfo-hexofuranoses (105 and 107), which, on treatment with lithium aluminum hydride, gave cis- and frans-3-deoxy-3-C-(fluoromethyl)-1,2 5,6-di-O-isopropylidene-a-D-rtbo- (102 and 104) and -xyZo-hexofura-... 

Alcohol-free potassium ferf-butoxide, obtained from the MSA Research Corporation, Callery, Pennsylvania, should be weighed and transferred under anhydrous conditions. 

Some breakthrough was finally achieved by using Pd2(dba)3 as the Pd complex, tris(tert-butyl)phosphine as the ligand, and sodium ferf-butoxide as the base [90]. This combination of reagents proved to bring about the synthesis of unsubstituted phenazine (137) by reaction of two molecules of 2-bromoaniline (131). Remarkably, no reaction takes place under the conditions of the 133 117 transformation. Currently the scope and limitations of this new sequential inter-Zintramolecular AT-arylation for the synthesis of AT-heterocycles... 

Feuer and co-workers extended their studies to the alkaline nitration of a,Nitration with potassium ferf-butoxide and amyl nitrate in THF at —30 °C yields the corresponding dipotassium salt of the a,nitronate salts from these reactions are isolated via methanol-induced precipitation from the aqueous reaction liquors, a process which also separates the product from impurities. These salts undergo hydrolysis on treatment with aqueous potassium hydroxide, and subsequent acidification yields the corresponding Q, y-dinitroalkane. This route has been used to synthesize 1,4-dinitrobutane (27) from apidonitrile (95) in 30 % overall yield. 

To say ferf-butoxide is a smaller base and removes a proton from the alternative site is not sufficient. If it can remove a proton from the hindered position, then it can also remove one from the less-hindered position, so we ought to get a mixture of the two possible products. Here, we need to remember that although LDA forms the enolate anion in an irreversible manner, enolate anion formation using ferf-butoxide is an equilibrium and, therefore, reversible. Therefore, we see formation of the more favonrable prodnct, i.e. that with the five-membered ring. 

Treatment of the Michael adducts 94 with a strong base such as potassium ferf-butoxide yielded the 2-azaazulenes 131 in 48-70% yield, respectively (Scheme 43) [60]. 

In all cases the reactions proceeded smoothly at - 78 °C and the alcohols 235 with an (k)-configuration at the newly formed stereogenic center were the major diastereomers in all cases. When the reaction mixtures were allowed to reach room temperature, mixtures of the alcohols 235 and the lactones 236 were isolated instead. The lactones 236 were exclusively obtained when the corresponding alcohols 235 were treated with potassium ferf-butoxide. On the other hand, treatment of the alcohols 235 with dilute hydrochloric acid afforded mixtures of the alkenes 237 and the tetracyclic compound 238, the structure of which was confirmed by X-ray analysis. 

Fluoromethane would presumably tend to react by an Sjv2 process rather than by deprotonation, whatever the base used. On the other hand, potassium ferf-butoxide ° and fluoride suffice already to set free the trilluoromethyl anion from trifiuoromethane (fiuoroform). Being extremely fragile, the trifluoromethanide must be trapped in situ, for example by addition to iV,iV-dimethylformamide. 

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